1. Field of the Invention for Amination
The present invention concerns the mono- and/or poly-amination of electrophilic aromatic compounds. In particular, the present invention concerns the discovery and use of quaternary hydrazinium salts, e.g., 1,1,1-trisubstituted hydrazinium salts, for vicarious nucleophilic substitution (VNS) of hydrogen, which provide new and improved syntheses of mono and/or poly amino-aromatic compounds, such as 1,3-diamino-2,4,6-trinitrobenzene (DATB) and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). The present invention also concerns the use of 4-amino-1,2,4-triazole, as well as hydroxylamnine and its O-alkyl derivatives, to provide new and improved syntheses of aromatic amine compounds, such as DATB and TATB, by VNS reactions.
2. Description of the Problem and Related Art
The amination of organic aromatic compounds (both carbocyclic and heterocyclic) occurs according to a number of reactions known in the art. However, the methods of the art often are dangerous, require special equipment, have problematic side reactions, separation problems, hazardous reagents, environmental problems and the like.
Some explosives are more sensitive to shock and heat than others having a similar structure. Studies of explosives based on the benzene ring include, for example, 1,3,5-trinitrobenzene (TNB), 2,4,6-trinitrotoluene (TNT), 1-amino-2,4,6-trinitrobenzene (TNA) (aka picramide), 1,3-diamino-2,4,6-trinitrobenzene (DATB) and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). Although these compounds have much in common, the shock initiation thresholds, that is, the shock pressure required to cause detonation in 50% of the tests, vary widely. Table 1 shows the pattern.
TABLE 1 ______________________________________ SHOCK INITIATION THRESHOLD OF EXPLOSIVES Compound Pressure (kilobars) ______________________________________ TNB 17 TNT 21 TNA 30 DATB 46 TATB 75 ______________________________________
While not wanting to be bound by theory, it appears that adding amino groups to a nitro-substituted benzene ring raises the shock initiation threshold. This pattern occurs, because as the networks of hydrogen bonds increase, the networks absorb energy from a shock front and reduce the amount of shock that goes to the ring itself. See W. Worthy in "Shock Sensitivity of Explosives Clarified", Chemical and Engineering News, p. 25, (Aug. 10, 1987) for further discussion.
It follows that DATB and TATB are highly desirable, insensitive explosives that are used primarily in specialty applications. Part of the reason that they are used in special as opposed to general explosive applications is high cost. They are too expensive to use in ordinary applications when other less expensive explosives can be used. One reason that TATB is expensive is that it is usually prepared from 1,3,5-trichlorobenzene which is expensive and is not generally available from domestic suppliers. The ammonium chloride byproduct (NH.sub.4 Cl) is difficult to remove completely and may cause compatibility problems in certain types of ordnance (e.g., U.S. Pat No. 4,032,377).
Alternative preparations of aminoaromatic compounds were sought, and include:
T. M. Benziger, U.S. Pat No. 4,032,377 discloses a preparation of TATB by nitration of 1,3,5-trichlorobenzene to 1,3,5-trichloro-2,4,6-trinitrobenzene followed by treatment with ammonia to produce TATB. This patent also discloses the use of water to separate the byproduct ammonium chloride.
D. G. Ott and T. M. Benziger, U.S. Pat No. 4,952,733 and Journal of Energetic Materials, vol. 5, pp. 343-354 (1987) disclose a preparation of TATB by nitration of 3,5-dichloroanisole to produce 3,5-dichloro-2,4,6-trinitroanisole which is chlorinated to give 1,3,5-trichloro-2,4,6-trinitrobenzene which is ammonolyzed to give TATB.
Additional art of interest includes, for example:
R. L. Atkins et al., in U.S. Pat No. 4,248,798 disclose a new method for preparing pentanitroaniline (PNA) and triaminotrinitrobenzene (TATB) from TNT. TNT is first reduced using H.sub.2 S to 4-amino-2,6-dinitrotoluene then nitrated using nitric acid/sulfuric acid to pentanitroaniline followed by reaction with ammonia to produce the TATB.
M. Makosza et al., review and discuss "Vicarious Nucleophilic Substitution of Hydrogen", in Accounts of Chemical Research, vol. 20, pp. 282-9 (1987), and teach the substitution of polynitrobenzene structures with a number of non-nitrogen containing vicarious nucleophilic substitution reagents. No nitrogen-containing reagents are disclosed or suggested.
A. R. Katritzky and K. S. Laurenzo, Journal of Organic Chemistry, vol. 51, pp. 5039-5040 (1986) disclose mono-amination of nitrobenzene and some substituted nitrobenzenes to give 4-nitroanilines by VNS reactions. The same authors, in the Journal of Organic Chemistry, vol. 53, pp. 3978-3982 (1988) disclose the use of a series of 4-(alkylamino)-1,2,4-triazoles to transfer the alkylamino group to the 4-position of nitrobenzene and 3-substituted nitrobenzenes by VNS. Only monoamination is taught or suggested.
T. Urbanski et al., Journal of Scientific and Industrial Research (India), vol. 37, p. 250-5 (1978), disclose the standard preparation and properties of several heat resistant explosives including DATB and TATB.
J. R. Holden et al., U.S. Naval Ordnance Laboratory, White Oak, Md., NAVORD Report 6299 (March 1959), disclose the properties of DATB.
S. K. Yasuda et al., in Journal of Chromatography, vol. 71, p. 484-86 (1972) discuss the separation and identification of 12 impurities of TATB by two dimensional thin-layer chromatography.
M. Makosza et al., Journal of Organic Chemistry, vol. 57, p. 4784-5 (1992), disclose the mono-amination of nitrobenzenes with sulfenamides via vicarious nucleophilic substitution of hydrogen. See also U.S. Pat. No. 5,262,539.
W. P. Norris et al., "CL-14, A New Dense, Insensitive, High Explosive", Naval Weapons Center, China Lake, Calif., Report No. TP 6597 (Unclassified), May 1985, disclose the use of hydroxylamine to di-aminate 4,6-dinitrobenzofuroxan (DNBF) thereby producing 5,7-diamino-4,6-dinitrobenzofuroxan (CL-14).
R. L. Atkins et al., in the Journal of Organic Chemistry, vol. 51, pp. 3261-3266 (1986), disclose the synthesis of a number of polynitro compounds, including TATB. Pentanitroaniline is reacted with ammonia to produce TATB.
T. R. Gibbs et al., LASL Explosives Properties Data (University of California Press, Berkeley, Calif., 1980.
B. M. Dobratz, LLNL Explosives Handbook: Properties of Chemical Explosives and Explosive Simulants, Lawrence Livermore National Laboratory, Livermore, Calif., UCRL-52997 (Mar. 16, 1981).
German patent, Ger. Offen DE 3,612,238) teaches the use of TATB to prepare components of lyotropic liquid-crystal phases for use in display devices.
TATB is also valuable in non-explosive applications. K. Praefake and B. Kohne, Ger. Offen. DE 3,612,238 disclose the use of TATB to prepare hexaaminobenzene derivatives which are used as components of lyotropic liquid-crystal phases, which can be used in display devices.
Additional art of interest includes, for example:
J. Meisenheimer et al., in Chemische Berichte, vol. 39, pp. 2533-2542 (1906) describe the di-amination of 1,3-dinitrobenzene with hydroxylamine under basic conditions to yield 2,4-dinitro-1,3-phenylenediamine. S. Seko in U.S. Pat. No. 5,466,871 extends the work of Meisenheimer by employing O-alkylhydroxylamines to monoaminate substituted nitrobenzene derivatives thereby providing various nitroanilines.
J. A. Hoffman and C. F. McDonough, U.S. Pat. No. 3,278,604 and J. C. Dacons et al., in U.S. Pat No. 3,394,183 both disclose the preparation of DATB via sulfonation and nitration (2 steps) of 1,3-dimethoxy-2,4,6-trinitrobenzene (DMTNB) which is then aminated to give DATB.
J. G. Kaey and E. F. V. Scriven in Chemical Specialties USA 91 Symposium disclose the regiospecific synthesis of 1-substituted-1,2,4-triazoles using 4-amino-1,2,4-triazole.
None of these references individually or collectively teach or suggest the present invention.
All patents, applications, articles, standards, references, etc., cited in this application and incorporated herein by reference.
There is a need for new processes which are milder and more environmentally benign to convert aromatic compounds to mono- and/or polyamino aromatic compounds, such as DATB, TATB or mixtures thereof. The present invention provides such useful processes which avoid strong acids (H.sub.2 SO.sub.4, HNO.sub.3), avoid elevated temperatures (100-150.degree. C.), and avoid the need for noxious materials such as ammonia, thionyl chloride or hydrogen sulfide. The present invention provides useful processes which are also environmentally benign.